Abstract

Behavioural plasticity of top marine predators to adapt to seasonal changes in the behaviour of their prey is little understood. Here, we used data from 16 multi-sensor archival tags attached to killer whales in 2005, 2006 and 2009 to evaluate whether and how their feeding behaviour varied according to seasonal life-stages (overwintering, feeding and spawning) of their herring prey. Feeding periods with tail slaps were consistently characterized by non-directional movement with the production of calls and echolocation clicks, but angular deviation in heading during feeding periods was lower during overwintering than spawning prey life-stages. Tail slaps were produced more often at depths >10 m in the feeding and spawning prey life-stages, while during overwintering, they often occurred at